Many health conscious foods and drinks have been developed in recent years and have also been commercially available. For obtaining real products that produce an actual feeling of health functions, an amount exceeding an effective amount is required to be added, as a matter of course. So-called functional components, which impart useful effects to human bodies, are often accompanied with bitterness, as has been said that “bitters do good to the stomach” since long ago. These functional components, when contained in effective amounts or more in foods and drinks, reduce palatability and reduce the appeal of the products.
Hops, which are the origin of a bitter component in beer, have also been used as a folk medicine since long ago and are known to have various health functions such as sedative effect and stomachic effect. An extract obtained from this hop, when contained in the predetermined amount or more in foods and drinks, causes peculiar strong bitterness and might impair palatability.
Many attempts have been reported for removing or reducing such bitterness. Examples of substances used as bitterness reducing materials include phosphatidic acid (trade name “BENECOAT BMI”, Kao Corp.) and L-ornithine (Food Science Journal, No. 317, p. 54, 2004). However, their effects are not always strong when used alone. Particularly, it has been difficult to reduce the bitterness of the hop extract. Moreover, in a masking technique using a sweetener such as sucralose or thaumatin as an additive (Japanese Patent Laid-Open Publication No. 2008-99682), bitterness is masked to some degree by sweetness. However, its use is limited due to the strong sweetness.
For pharmaceutical products, usually, sugar coating is mainly performed for tablets. In addition, a film coating technique, microencapsulation, or the like is used. However, it has been difficult to completely mask bitterness. Furthermore, these techniques cannot be used for liquid preparations, like drinks. Thus, the reduction of bitterness is still a significant challenge to the field of foods and drinks or pharmaceutical products.